Screw-driver



( NoModeL) F J OQLVIN SCREW DRIVER.

' No. 279,917. Patented June 26, 1883.

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v NITED STATES PATENT O FICE.

FREDERICK J. COLVIN, OF HAMDEN, COI. INEC'I.ICUI.

SCREW-DRIVER.

SPECIFICATION forming part of Letters Patent No. 279,917, dated June 26, 1883. Application filed April 5, 1883. (No model.)

To all whom it may concern p Be it known that I, FREDERICK J. GOLVIN,

- a citizen of the United States, residing at Hamden, in the county of New Haven and State of Connecticut, have invented a new and useful Screw-Driver, of which the following is a specification, reference being had to the accompanying drawings.

This invention relates to screwdrivers, and has for its object to provide a simple, inexpensive, durable, and efficient device having removable points that can be readily secured in position to fit varying sizes grooves, and which, if broken, will not impair I 5 the utility of the whole device, but canbe conveniently removed and a new point be substituted. I

In the drawings, Figure 1 is a perspective view of a screw-driver embodying my improvements. Fig. 2 is alongitudinal sectional View of the same.

taken near the point of the blade. Fig. 4. is a perspective View, illustrating my invention when adapted for use in connection with a brace.

Referring to the drawings, A designates the handle of my improved screw-driver, to which the stem or blade B is secured in any suitable manner. The latter is preferably enlarged to.- ward and at its point or head C, as shown,and

is formed with a longitudinally-disposed kerfor slit, D, formed parallel with the width of the blade. The head C is elastic, so that the side portions, E E, formed by the separatingkerf D, can be compressed together. Ascrewthreaded perforation, F, is formed through the head C at right angles to the kerf D, and in this perforation works a screw-threaded bolt,

G, to the head of which is secured an operat- 4o ing-bar, H, having its free end I turned up at right angles to its main portion, and preferably milled, as shown at J, to give hold to the thumb when the bar is operated to turn the bolt G, and compress or release the tension of the spring portions E E. Aflange or washer, K, is arranged at the head of the bolt G to eleof screw-head.

Fig. '3 is a cross-section vate the rod or bar Habove the surface of the blade B, so that it will not mar the latter in turning. The portions E E are provided at their ends on their inner faces with a shoulder, L, 011

which the point M abuts when it is inserted between the two portions E E, and is secured in position by simply compressing the latter. Varying sizes of points M are provided, any one of which can be readily secured in position for use'on different sizes of screw-s. The handle A is provided with a recess or chamber, arranged to contain the points M when not in use, which is covered by a pivoted plate, 0, having a hook end, I, that engages a spring pin, Q, arranged in a recess, R, in the handle.

Under some circumstances the blade B is not secured to a handle, but is formed with a squared tapering end, S, by which it can be secured in a brace for use in heavy work.

I claim as my invention- 1. The combination, with the stem or blade having a longitudinally-disposed kerf in its end, shoulders formed in the inner faces of the side portions divided by this kerf or slit, and a screw-threaded perforation formed at right an les to the kerf, of a screw-threadedbolt I wo rking in the said perforations and provided with an operating-bar, as set forth. 2. The combination of the stem or blade having the slit or kerf in its end, the shoulders in the inner faces of the side pieces, and the screw-threaded perforation at right angles to the kerf, the removable point inserted in the kerf against the said shoulders, the screwthreaded bolt working in the perforation, and the operating-bar secured to the head of the bolt and elevated above the surface of the stem or blade, as set forth.

In testimony that I claim the foregoing as my own I have hereto affixed my signature in presence of two witnesses.

FREDERICK J. COLVIN.

Witnesses:

HENRY A. OoLvIN, ELLSWORTH B. Coornn. 

